JAKARTA, June 25 (Reuters) - An undersea earthquake measuring 6.0 on the Richter scale rocked eastern Indonesia on Monday, but there were no reports of damage and there was no risk of a tsunami, a Meteorology and Geophysics Agency official said. The epicentre of the quake lay 45 km (28 miles) northwest of Labuhanbajo in East Nusa Tanggara province on Sumba island at a depth of 181 km, an analyst at the agency said. Earthquakes are frequent in Indonesia, the world's fourth most populous country. Its 17,000 islands sprawl along a belt of intense volcanic and seismic activity, part of what is called the "Pacific Ring of Fire".
